JPH11309766A - Method and apparatus for injection molding in-mold decorating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method and an apparatus for injection molding in-mold decorating wherein a cycle time is shortened and feeding of an in-mold decorating sheet on a mold is stabilized. SOLUTION: After an in-mold decorating sheet S is fed on a mold, the in- mold decorating sheet is heated at its heat distortion temp. or higher and after it is made to be laid along the cavity face of the mold by drawing a vacuum from the inside of the mold, the mold is clamped and a resin is injected to adhere the in-mold decorating sheet with the resin. In the technology for the injection molding simultaneous in-mold decorating, before the in-mold decorating sheet is fed on the mold, the in-mold decorating sheet is preheated at a temp. below the heat distortion temp. by a preheater 4. An apparatus for the injection molding simultaneous in-mold decorating is provided with a sheet preheater 4, a sheet heating device 70 for heating the in-mold decorating sheet at its heat distortion temp. or higher, a sheet feeding device 5 for feeding the in-mold decorating sheet to a preheating position and furthermore, feeding it in the mold, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a painted plastic molded product and a production apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, injection molding simultaneous painting techniques for forming a pattern or the like on the outer surface of a plastic molded article using a painted sheet at the same time as molding are performed in various modes. For example, in Japanese Patent Publication No. 50-19132, a female mold provided with a vent hole for vacuum molding is used as a vacuum molding mold, and a painted sheet is fed and fixed onto the female mold, and then heated by a heater plate. After softening, pre-forming the painted sheet by vacuum forming and aligning it with the cavity surface of the female mold, clamping the male and female molds, injecting the molten resin into the cavity formed by both molds, opening the mold A method is disclosed in which a molded sheet is taken out, and the painted sheet is integrated with the surface of the molded article simultaneously with the injection molding. Further, for example, Japanese Patent Application Laid-Open No. 6-3159
In Japanese Patent Publication No. 50, a continuous band-shaped painted sheet unwound from a roll is fed between a pair of dies composed of male and female dies in an open state, and the periphery is fixed to a female parting surface with a sheet holding frame. After supplying the painted sheet on the female mold, the heater plate is moved between the two molds from the retracted position outside the mold,
The painting sheet is heated and softened in a non-contact manner in opposition to the painting sheet supplied on the mold, and the painting sheet is preformed in an injection molding die and is aligned with the cavity surface of the female mold. By retracting to the external retreat position, clamping both molds, injecting resin into the cavity formed by both molds, taking out the molded product after opening the mold, the molded product surface is painted with a sheet simultaneously with molding. A technique for painting is disclosed. In each of these forms, the painted sheet is preformed by an injection molding die, and the heating and softening for the preformed sheet is performed after the sheet is supplied onto the mold.

In Japanese Patent Publication No. 4-42172,
In the form of pre-molding a painted sheet with an injection molding die, a heater plate that reciprocates between a retracted position outside the mold and the inside of the mold to heat and soften the painted sheet is provided with a through hole on its heating surface to paint. An object having a structure capable of adsorbing the sheet and further pressing and fixing the painted sheet to the heating surface by the frame member is used. When the heater plate is in the retracted position, the painting sheet is held on the heating surface, and when moving into the mold, the painting sheet is moved while holding the painting sheet, so that the painting sheet is supplied onto the mold and heated. A technique for softening is disclosed.

[0004]

However, after supplying a painted sheet at room temperature and below the heat distortion temperature on a mold as disclosed in Japanese Patent Publication No. 50-19132 and JP-A-6-315950, it is heated. In the case of using a painted sheet having good heat resistance or a thick painted sheet, it takes a long time to heat the painted sheet, and there is a problem that the cycle time becomes longer and the productivity is reduced. On the other hand,
In Japanese Patent Publication No. 172, since the painted sheet can be heated from the time when the heater plate is in the retracted position, the heating time after the heater plate is moved into the mold can be shortened accordingly, but the painted sheet is sucked and held on the heating surface. For this reason, the traces of the ventilation holes provided on the heating surface may be formed on the softened painted sheet, resulting in poor appearance. In addition, especially in large size and thick painted sheets, the vacuum for holding the painted sheets by suction may leak or the painted sheets may be turned up.When transporting the softened painted sheets between the male and female molds, It was difficult to completely suppress deformation and distortion of the painted sheet. Further, when transferring the painted sheet to the female mold which is to be a preforming mold, the heater plate releases suction of the painted sheet by suction from the air hole, and conversely blows out compressed air from the air hole. Moreover, since the painted sheet has already been heated, the delivery of the painted sheet becomes unstable due to wrinkles in the painted sheet as traces of the painted sheet leaving the heated surface in order with a slight time difference. was there. Further, in the case of a painted sheet having an adhesive layer on the back side, the adhesive layer was sometimes removed to the heater plate side. In view of the above, an object of the present invention is to provide a method and apparatus for simultaneous injection molding and painting in which the cycle time is shortened and the supply of the painted sheet onto the mold is stabilized.

[0005]

Therefore, in order to solve the above problems, in the simultaneous injection molding and painting method of the present invention, after supplying a painting sheet on a mold, the painting sheet is heated to a temperature not lower than the heat deformation temperature of the sheet. After drawing the painted sheet along the cavity surface of the mold by evacuation from inside the mold, the mold is clamped and the resin in the fluid state is injected into the cavity, and the painted sheet and the resin are bonded together. In the method, prior to feeding the painted sheet onto the mold, the painted sheet was preheated to a temperature below the heat distortion temperature of the sheet. as a result,
By shortening the heating time of the pre-heated painting sheet after the pre-painted painting sheet is supplied between the molds, the cycle time can be shortened and the productivity is improved. In addition, since the preheating of the painted sheet is lower than the thermal deformation temperature of the painted sheet, deformation and distortion of the painted sheet when the preheated painted sheet is supplied onto the mold can be suppressed, and the painted sheet can be stably placed on the mold. Can be supplied in a regular manner.

In the above method, when the preheated painted sheet is supplied into the mold, the painted sheet is gripped at least at both ends in the width direction with respect to the conveying direction of the painted sheet,
By supplying the sheet with the length of both sides in the width direction of the painting sheet constant, deformation and distortion of the painting sheet when supplying the painting sheet onto the mold are reliably prevented, and the painting sheet is extremely It can be supplied stably on the mold. Also,
If the pre-heating and heating of the painting sheet is performed by non-contact heating, the painting sheet is fused to the heater with its adhesive layer or the like, and the supply of the painting sheet onto the mold does not become unstable, There is no occurrence of poor appearance of the molded product due to the trace of the painted sheet contacting the heater.

[0007] The simultaneous injection molding painting apparatus of the present invention comprises:
After supplying the painted sheet on the mold, the painted sheet is heated to a temperature equal to or higher than the heat deformation temperature of the sheet, and the painted sheet is made to conform to the cavity surface of the mold by evacuation from the inside of the mold. In an injection molding simultaneous painting apparatus for performing an injection molding simultaneous painting method for injecting a resin in a flowing state and bonding a painted sheet and a resin, the painted sheet before being supplied onto a mold is subjected to thermal deformation of the sheet. A sheet preheating means for preheating to a temperature lower than the temperature, a sheet heating means for heating the preheated painted sheet supplied into the mold to a temperature equal to or higher than a heat deformation temperature of the sheet, and a painting sheet supplied to a preheating position by the sheet preheating means And a sheet supply unit that further supplies the preheated painted sheet into the mold. As a result, the above injection molding simultaneous painting method was implemented,
Productivity can be improved by shortening the cycle time while maintaining a stable supply of painted sheets.

In addition, the simultaneous injection molding painting apparatus of the present invention
In the above apparatus, the sheet supply means, when supplying the preheated painted sheet into the mold, grips the painted sheet at least at both ends in the width direction with respect to the transport direction of the painted sheet,
The sheet was supplied with the lengths of both sides in the width direction of the painting sheet constant. With this configuration, even if the painting sheet is preheated, the painting sheet maintains its length in the width direction, thereby reliably preventing deformation and distortion of the painting sheet when supplying the painting sheet onto the mold, The painted sheet can be supplied to the mold extremely stably. Further, if the pre-heating and heating of the painting sheet are performed by non-contact heating, the painting sheet may be fused to the heater with its adhesive layer or the like, and supply of the painting sheet to the mold may become unstable. In addition, the apparatus does not suffer from poor appearance of the molded product due to the trace of the painted sheet contacting the heater.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a simultaneous painting method and apparatus according to the present invention; FIG. 1 to FIG. 5 are conceptual diagrams conceptually explaining the injection molding simultaneous painting method and apparatus of the present invention in one embodiment. FIG. 1 is a side view showing the overall configuration of the simultaneous injection molding painting apparatus of the present invention. FIG. 2 is a perspective view showing the periphery of a preheater 4 and a sheet supply device 5 therein. FIG. 3 shows an endless annular chain 50 and a sheet holding chuck 6 in the sheet feeding apparatus.
FIG. FIG. 4 is a partially enlarged cross-sectional view illustrating the endless annular chain 50 and the sheet holding chuck 60 of FIG. 3 and the guide groove 36 provided in the female die 12. FIG.
FIG. 4 is a partially enlarged cross-sectional view for explaining operations of the endless annular chain 50 and the sheet gripping chuck 60 of FIG.

In the apparatus described in these drawings, the injection molding die used is such that the fixing surface of the painted sheet on the female die is not a flat surface, but is directed toward the male side in a substantially "C" shape in side view. This device is capable of performing “deformation feeding” of a painting sheet, which is fixed to the convexly curved parting surface 14. Of course, in the same device, depending on the shape of the molded product to be manufactured,
It is also possible to use an injection mold having a flat parting surface or a concave parting surface toward the male side.

In addition, the simultaneous injection molding and painting apparatus of the present invention illustrated in the drawings includes a preheater 4 as a sheet preheating means for preheating a painted sheet before being supplied onto a mold to a temperature lower than a thermal deformation temperature of the sheet. And a heater 70 serving as a sheet heating means for heating the preheated painted sheet supplied into the mold to a temperature equal to or higher than the thermal deformation temperature of the sheet; and supplying the painted sheet to a preheating position by the preheater 4 and further after the preheating. And a sheet supply device 5 as sheet supply means for further supplying the painted sheet into the mold. In the sheet supply device 5, when the preheated painted sheet is supplied into the mold, the painted sheet is gripped at least at both ends in the width direction with respect to the conveying direction of the painted sheet, and the length of both sides in the width direction of the painted sheet is measured. Is transported by a pair of endless annular chains 50 provided with a plurality of sheet gripping chucks 60 so that the sheet is supplied in a constant state. The preheater 4 and the heater 70
Are devices for preheating and heating the painted sheet by non-contact heating.

For example, the simultaneous injection molding painting apparatus of the present invention having the above-described configuration is combined with an existing injection molding machine, similarly to a conventionally known injection molding simultaneous painting apparatus. By preparing a mold corresponding to the intended molded article, attaching the mold to the injection molding machine and performing injection molding, a desired painted plastic molded article painted with the painted sheet can be obtained.

[0013] The simultaneous painting apparatus for injection molding of the present invention comprises:
It is not limited to the configuration illustrated as an example in FIGS.
Basically, a sheet preheating means for preheating the painted sheet before being supplied onto the mold to a temperature lower than the heat deformation temperature of the sheet,
A sheet heating means for heating the preheated painted sheet supplied into the mold to a temperature equal to or higher than the thermal deformation temperature of the sheet; and supplying the painted sheet to a preheating position by the sheet preheating means, and further placing the preheated painted sheet in the mold. And a sheet supply means for supplying the sheet.
Alternatively, the other components can appropriately adopt various techniques in the conventionally known simultaneous injection molding painting apparatus.
For example, a vacuum source or the like for vacuum forming a painted sheet may or may not be provided as a component. Also, the painting sheet to be used may be a method and an apparatus adapted to the form of preheating, heating, preforming and injection molding in a continuous strip shape, or a sheet-like painting sheet may be set from the beginning and preheated. A method and an apparatus suitable for the form of heating, preforming and injection molding may be used, and the form of the painted sheet is arbitrary.

First, the injection mold used in the present invention is, in the embodiment exemplified here, an injection mold composed of a pair of female molds 12 and male molds 25, and is made of a metal such as iron or ceramics. The female mold 12 is fixed to the movable platen 11 of the injection molding machine. The movable platen 11 moves forward and backward in the horizontal direction (Y direction) of the drawing by the ram 9 of the fluid pressure cylinder, and the like.
The female mold 12 approaches and separates from the male mold 25, and becomes a mold-clamped state and a mold-opened state (the state of FIG. 1). Of course, as for the form of the simultaneous injection molding painting apparatus of the present invention, as shown in FIG. 1, the injection molding machine combined with this apparatus moves vertically in addition to the horizontal type in which the movable mold (female mold 12) moves horizontally. A form corresponding to a vertical type may be used. In this case, the female mold 12 is shown in FIG.
The cavity 13 has a relatively shallow side view generally "C" -shaped cavity 13 corresponding to the painted product to be obtained, and a parting surface 14 on the outer peripheral side of the cavity 13. The parting surface 14 forms a substantially convex (mountain-shaped) curved surface that projects toward the male mold 25 (Y direction) when viewed from the side. The cavity 13 of the female mold 12 has grooves or holes in the surface of the cavity 13 for vacuum forming the painting sheet. The ventilation hole may be provided on the parting surface portion inside the sealing O-ring provided on the parting surface. The vent hole is connected to a vacuum source (not shown) such as an external vacuum pump.

On the other hand, the male mold 25 is fixed to a fixed platen 31 of an injection molding machine as shown in FIG. 1, and an injection nozzle 32 enters the bottom side of the male mold to form both male and female molds at the time of mold clamping. The cavity is filled with a resin in a flowing state by melting or the like. The male mold 25 has a core portion 33 corresponding to the shape of a painted product and a parting surface 34 that is concaved in a “C” shape when viewed from the side. The female mold 12 has
In order to press and fix the painted sheet S against the parting surface 14 of the female die 12, a clamper 20 similar to the parting surface 14 and having a rectangular frame shape in a front view and a substantially "L" shape in a side view is provided. It is. The clamper 20 moves four connecting rods 24 slidably fitted into through holes near four corners of the female mold 12 in a direction perpendicular to the parting surface 14 of the female mold 12 by a driving mechanism (not shown). The drawing sheet is moved forward and backward in the Y direction) to press and fix the painting sheet supplied to the gap between the parting surface and the clamper 20 against the parting surface. The supply of the painting sheet onto the mold is completed when the clamper is fixed.

After the sheet supply device 5 which is one component of the simultaneous injection molding painting apparatus of the present invention supplies the painting sheet to the preheating position by the preheater 4, the preheated painting sheet is removed from the female die 12 by the preheating heater 4. It is supplied on the parting surface 14. The sheet feeding device 5 here includes a base frame 6 as shown in FIG. 1, the base frame 6 is connected and fixed to a movable platen 11 by a connecting member 7, and the base frame 6 is a female mold 12
Via a rail 3 on a support frame 1 installed on the left side of
It moves forward and backward in the horizontal direction of the drawing (Y direction) integrally with the forward and backward movement of the female mold at the time of opening and closing the mold. As shown in FIG. 2, a pair of connecting plates 8 which are a part of the sheet feeding device 5 are connected below the female mold 12, and each connecting plate 8 has a pair of left and right sprocket wheels 42 and 43.
I support.

On the base frame 6, there is provided an unwinding machine which is loaded with a roll R of the painting sheet S and can apply an appropriate back tension to the painting sheet, and guides one or a plurality of continuous belt-like painting sheets S from the roll R. It is unwound through rollers 48. Then, in order to supply one shot of the unwound painting sheet S onto the parting surface 14 of the female die 12 using a pair of left and right endless annular chains 50, the base frame 6 is provided with a pair of left and right sprocket wheels. 41, 4
4,45. In addition, for example, a pair of sprocket wheels 41 are rotationally driven by a rotational drive source (not shown) such as a stepping geared motor,
The endless annular chain 50 is moved. The pair of left and right endless annular chains 50 have the same size and shape on the left and right, and are wrapped around the sprocket wheels 41, 42, 43, 44, 45 in an L-shape as a whole when viewed from the side. Of course, the distance (width) between the left and right endless annular chains 50 is constant.

As shown in FIGS. 3 and 4, the endless annular chain 50 is provided with support members 61, for example, at every two pitches. A roller 63 is attached, and a sheet gripping chuck 60 for gripping both ends in the width direction of the one-shot picture sheet S is provided above the support member 61 at a predetermined pitch (for example, 5 pitches). It is. The required number of sheet gripping chucks 60 are provided only in a specific range of each of the endless annular chains 50 on both the left and right sides so that the pictorial sheet S having a length of one shot can be gripped.
The sheet feeding device 5 includes an endless annular chain 50.
The portion where the sheet gripping chuck 60 is provided is located on the female parting surface 14 via the preheating position from the feeding position, which is the conveyance start position of the one-shot cut of the painted sheet, via the preheating position. Reciprocate between the feeding position. The preheating position at which the painted sheet is preheated on the preheater 4 is a position where the painted sheet is conveyed to some extent from the payout position (see the painted sheet S in FIG. 1), but the payout position is the preheating position as it is. Sometimes.

Then, the endless annular chain 50 grips one shot of the pictorial sheet with the sheet gripping chuck 60 and conveys it onto the parting surface 14 of the female mold 12, and the clamper 20 removes the pictorial sheet. The parting surface 1
4, when the supply of the pictorial sheet onto the mold is completed, the sheet gripping chuck 60 releases the gripping of the pictorial sheet, the endless annular chain 50 rotates in reverse, and the sheet gripping chuck 60 Return to the original payout position to prepare for the next shot.

As described above, in the method and apparatus for simultaneous painting by injection molding of the present invention exemplified here, the conveying form of the painted sheet is such that only the both ends of the painted sheet come into contact by using a chain for the painted sheet conveying means. Since the sheet is not conveyed without touching other portions and pulling the leading end of the sheet, the sheet is not subjected to unnecessary tension in the conveying direction during the conveyance. Therefore, even when the prepainted sheet is supplied after being preheated as in the present invention, the prepainted sheet that is less than the thermal deformation temperature but is easily stretched from room temperature is not stretched,
The shape can be supplied stably. In addition, even when the surface (parting surface) for fixing the picture sheet on the mold is non-planar (but a quadratic surface) such as a convex or concave curve, there is an advantage that the picture sheet can be supplied. In addition, a conveyance form that can supply such a painted sheet with a constant length in the conveyance direction may be a long body that is invariable in length and bendable, such as a rope or a belt, instead of using a chain. Also, needless to say, in the method and apparatus for simultaneous painting by injection molding of the present invention, the painting sheet transporting means may be a chain or the like other than a length-invariable and bendable body. For example,
In the form of feeding with a fixed length, the rigid length of a metal plate or the like is invariable if the painted sheet fixing surface is flat and the painted sheet is linearly conveyed between the preheating position and the supply position on the plane. It may be conveyed by sandwiching and holding both ends of the painted sheet in the width direction from the front and back with a long body. Further, needless to say, if the stretch of the painted sheet can be ignored, the leading end of the painted sheet may be conveyed.

The preheater 4 for preheating the painted sheet at the preheating position is not particularly limited as long as it can heat the painted sheet to a temperature lower than the thermal deformation temperature. For example, conventionally known various heating means such as a heating wire heater, a ceramic heater, a sheet heating element, and a dielectric heater can be used. Also,
The preheater is preferably a non-contact heater, which is also a form of heating by radiant heat, but leaves no trace of contact with the heating surface of the preheater on the painted sheet or the final painted molded article, and the heating is efficient. Is good. In FIG. 1, the preheater is arranged so that non-contact heating is performed on the front side of the painted sheet (the side in contact with the injection resin is on the rear side). It may be arranged.

The temperature at which the painted sheet is heated during preheating is the heat distortion temperature (4.6 kgf specified by JIS K7207).
/ Cm ² bending stress). This is because if the painted sheet is heated to a temperature higher than the heat deformation temperature, the shape of the painted sheet becomes unstable when the painted sheet is transported from the preheating position to the supply position, and the painted sheet is stably supplied onto the mold. This is because it becomes difficult to do so. Even when the painted sheet is preheated and the conveying or preheating of the painted sheet is free on the front and rear or the center only on both sides of the painted sheet, or when the painted sheet is conveyed by pulling the leading end, When the value is less than the above, the painted sheet can be stably supplied without causing deformation, distortion, tear, and the like of the painted sheet. This is particularly true in the case of the latter transport mode in which the painted sheet is pulled and transported. Note that the preheating time is a special cycle time due to the preheating itself, which is done within the time that the painting sheet of the next shot is at the preheating position while the painting sheet of the previous shot is heated softening or injection molding. It is good because there is no extension. Further, the temperature setting of the preheating heater is preferably set to enable such a thing.

On the other hand, as the sheet heating means, the heating means of the heater for heating the painted sheet after being supplied onto the mold may be any of various conventionally known heating means such as a ceramic heater and a sheet heating element, similarly to the preheating heater. . The heater 70 as the sheet heating means illustrated in FIG. 1 is provided with a heater whose heating surface is bendable and can be non-planar. There is a structure that can be heated. Further, in the apparatus configuration of FIG. 1, the preheating heater serving as the sheet preheating means and the heater serving as the sheet heating means are provided as dedicated separate bodies. By forming them separately, the sheet preheating and the sheet heating can be performed separately at a more suitable time, at a more suitable temperature, or at a more suitable position.

The heating temperature of the colored sheet when the colored sheet is heated on the mold is determined by the heat distortion temperature (JIS K720).
7 at the time of 4.6 kgf / cm ² bending stress) or more. The heat deformation temperature is the minimum temperature necessary for softening by heating for vacuum-forming the painted sheet. By heating and softening the painted sheet above the thermal deformation temperature, the painted sheet can be plastically deformed to conform to the female cavity shape. However, if the heating temperature is too high and the painted sheet is melted, the painted sheet is broken or greatly distorted. Therefore, the heating temperature is preferably lower than the melting temperature (or melting point).

Hereinafter, the method and apparatus for simultaneous painting by injection molding of the present invention in the form illustrated in FIGS. 1 to 5 will be described in more detail.

First, the leading end of the continuous band-shaped picture sheet S unwound from the roll R is held at the leading end cut by the sheet cutter 56 by a sheet holding mechanism 55 such as a suction cup. Then, when there is a sheet gripping chuck 60 provided on the endless annular chain 50 at the feeding position, a sheet pulling mechanism 57 sliding on a guide rail (not shown) provided on the base frame 6 and running in the Y direction.
Holds the leading end of the continuous band-shaped painted sheet S held by the sheet holding mechanism 55, moves in the Y direction,
Pull out the picture sheet for one shot. At this time, each of the sheet gripping chucks 60 is in a gripping released state by the rollers 68 being pressed as shown in FIGS.
Next, the both ends in the width direction of the one-shot painting sheet S are
The sheet holding chuck 60 provided on the endless annular chain 50 holds the sheet. When the gripping is completed, the sheet pulling mechanism 57 may release the gripping of the painting sheet. In this state, the sheet cutter 56 cuts off one shot of the sheet S with one shot from the roll R side. Then, the endless annular chain 50 is appropriately fed in the Y direction according to the length of the painting sheet and the length of the preheating heater, and the painting sheet S is supplied from the feeding position to a predetermined preheating position facing the preheating heater 4. This state is shown in FIG.

When the preheating of the painted sheet is completed, the endless annular chain 50 is fed (in the direction of the rotation arrow attached to the sprocket wheel 41 in FIG. 1), and one shot of the sheet gripped by the sheet gripping chuck 60 is taken. The single-leaf painted sheet S is transported to a supply position facing the female parting surface 14. After the conveyance, the sheet S with the picture is fixed and held on the parting surface 14 by the clamper 20. This completes the supply of the painting sheet onto the mold. Thereafter, the endless annular chain 50 is fed in the reverse direction, and the sheet grip chuck 60 is returned to the feed-out position to prepare for the next shot of the painted sheet.

Incidentally, since the mold used here has a non-planar parting surface, the parting surface 1
On the fourth side, the endless annular chain 50, the large-diameter roller 62, the small-diameter roller 63, and the sheet gripper 60
A pair of left and right supply-side guide grooves 36 extending in the up-down direction (Z direction) while curving along the parting surface 14 is provided to guide the passage through. The left and right endless annular chains 50 and the large-diameter rollers 6 are also provided on the bottom side of the female mold 12.
A pair of left and right bottom-side guide grooves 38 extending in the up-down direction (Z direction) through which two or the like pass are provided.

FIGS. 3 and 4 are cross-sectional views of the female-side guide groove 36 in the XY plane of the female die. As shown in these drawings, the supply-side guide groove 36 is provided so that the endless annular chain 50 and the sheet holding chuck 60 are orthogonal to the sheet conveying direction.
It has a cross-sectional shape capable of regulating the position in the direction.
For this reason, the supply-side guide groove 36 has an intermediate wall 36A protruding in the groove width direction, and a lower portion (the fixed receiving piece portion 6) of the sheet gripping chuck 60 is located above (in the drawing) above the intermediate wall 36A.
5) has an opening groove 36a opened on the parting surface 14 whose position is regulated, and the large-diameter roller 62 and the small-diameter roller 63 provided on the endless annular chain 50 so as to sandwich the intermediate wall 36A are inserted and guided. The position regulating recess 3 in which the large-diameter roller 62 is loosely fitted in the intermediate wall 36A and the bottom wall portion.
6d and 36c are provided. This position regulating recess 36d,
The endless annular chain 50 and the sheet gripping chuck 60 move in two directions orthogonal to the sheet conveying direction, that is, the direction along the parting surface 14 curved in a convex shape (the vertical direction and the horizontal direction in FIG. Direction).

Further, the sheet gripping chuck 60 is provided as shown in FIG.
As shown in FIG. 5, a fixed receiving piece 65 projecting laterally above the support member 61 to receive the back side (lower side) of the painted sheet S, and to be positioned above the parting surface 14. Movable presser piece 66 rotatably supported by support plate 64
And a sheet grip portion comprising: Movable presser piece 66
Is fixed by the compression coil spring 67.
Are urged in the direction for holding the painting sheet S in the clamping state. Therefore, the painted sheet S gripped by the sheet gripping chuck 60 can be moved substantially along the convexly curved parting surface 14 of the female mold 12.

Further, when the clamper 20 presses and fixes the picture sheet S to the female parting surface 14 on the endless annular chain 50 side of the movable presser piece 66, the clamp 21 is provided in the recess 21 for avoiding interference. A suppressed roller 68 is provided. When the roller 68 is suppressed by the concave portion 21 of the clamper 20, the movable pressing piece 66 separates from the fixed receiving piece 65 against the urging force of the compression coil spring 67, and the sheet gripping chuck 60 moves the The grip is released (see FIG. 5).

The endless annular chain 50 is provided with a necessary tension as required, so as to eliminate slack.
In the embodiment shown in FIG. 1, a pair of tension applying sprocket wheels 46 that are in pressure contact with the endless annular chain 50 are provided below the female mold 12. By adjusting the position of the tension imparting sprocket wheel 46 with respect to the endless annular chain 50 (Y direction in FIG. 1), the endless annular chain 50 is adjusted.
Adjust the tension of. Further, the positions of the endless annular chain 50 and the sheet gripping chuck 60 with respect to the supply-side guide groove 36 of the female die 12 are uniquely determined. FIG.
As shown by the imaginary line, a sprocket wheel 47 for applying tension may be provided above the female die 12 (upstream side).

Next, the parting 1 of the female mold 12 is described.
4 is the heating and softening of the painted sheet S pressed and fixed by the clamper 20. In the embodiment illustrated here, since the parting surface 14 of the female mold 12 is a substantially convex curved surface, the heating heater 70 for heating and softening is rotated with respect to the holding case 75 as shown in FIG. The two heater plates, the movably held plate-shaped heating unit 71 and the second plate-shaped heating unit 72, are positioned on the heating surface of the bent and fixed picture sheet S.
Radiant heating by non-contact heating at approximately the same distance can be performed. The heater 70 shown in the heating position in FIG.
Although not shown, a heating position between the dies shown in FIG. 1 is heated by a fluid pressure cylinder or a guide rail and a driving mechanism, etc., and a retracted position outside the dies (e.g. Reciprocating between these positions so as to be positioned upward or laterally with respect to the both sides.

The painted sheet is heated to a temperature equal to or higher than the thermal deformation temperature to be heated and softened, and after completion of heating and softening of the painted sheet or after a certain period of time after the start of heating and softening, the air holes ( (Not shown), and the prepainted sheet is preformed so that the prepainted sheet is vacuum-formed and along the cavity surface 13 of the female mold 12. In addition, vacuum forming also includes vacuum / pressure forming. After the pre-forming of the painted sheet, the heater 70 is moved and retracted from between the two dies to a retracted position outside the dies. Thereafter, the female mold and the male mold are clamped, and a resin in a flowing state is injected and filled into a cavity formed by the molds. Normally, a runner and a gate (not shown) communicating with the injection nozzle are provided on the male mold side (not shown), and the resin in a flowing state is injected into the cavities formed by both molds through these. After the injection resin is solidified, the mold is opened to separate the female mold and the male mold. Then, a painted molded product in which the painted sheets are laminated is obtained.
In addition, especially when the painted sheet is a laminate sheet,
Excessive painted sheet that has protruded to the peripheral edge of the painted molded product is cut (trimmed).

The painted sheet that can be used in the present invention is not particularly limited as long as it is a laminate sheet or a transfer sheet, and various conventionally known painted sheets can be used, and are not particularly limited. In particular, the present invention is effective because a laminated type painting sheet is often thicker than a transfer sheet. Also, among the laminated type painting sheets, a thick painting sheet is more preferable. In the present invention, even in the case of such a painted sheet,
A paint molding can be manufactured with high productivity without prolonging the cycle time. Further, in the case of non-contact heating of preheating and heating of the painted sheet, even a painted sheet having a configuration having an adhesive layer,
It is possible to stably supply the painted sheet without the adhesive layer being thermally fused to the heater, and to obtain a painted molded article having no appearance defect due to the thermal fusion.

The laminated type painting sheet is a sheet having a configuration in which a base sheet has been subjected to decoration processing such as printing of a decoration layer or the like representing a pattern, a character, or the like. A resin sheet having moldability is typically used as the base sheet of the painted sheet. As the resin sheet, for example, polyamide resins such as nylon, ethylene-isophthalate-terephthalate copolymer, polyester resins such as polybutylene terephthalate, polypropylene, polyethylene, olefin resins such as olefin-based thermoplastic elastomer, vinyl chloride resin, acrylic Resin, ABS resin (acrylonitrile-
A single layer of a sheet of a thermoplastic resin such as butadiene-styrene copolymer) or a laminate of two or more layers is used. In addition,
The decorative layer is a printed pattern such as a character or a pattern, a colored opaque or transparent (colored or non-colored) paint layer, or a functional layer such as a hard layer, an anti-fog layer, or a conductive layer. It should be noted that these decorative layers are releasably supported on a base sheet, and after the injected resin and the painting sheet are adhered to each other, the base sheet is peeled off and used to form a transfer sheet. In order to carry it releasably, known means such as providing a release layer on the base sheet may be used.

As the molding resin, those known in the art of simultaneous injection molding and painting can be used, and there is no particular limitation. For example, in the case of thermoplastic resins, olefin resins such as polypropylene, polyethylene, and olefin-based thermoplastic elastomers, vinyl chloride resins, acrylic resins, ABS (acrylonitrile-butadiene-styrene copolymer) resins, styrene resins, and AS (acrylonitrile- (Styrene copolymer) resin, polycarbonate resin and the like, and as the curable resin, unsaturated polyester resin, curable acrylic resin, two-pack curable urethane resin, epoxy resin and the like. The thermoplastic resin is melted by heating and injected in a fluidized state, and the curable resin is injected in a fluidized state as an uncured liquid material appropriately heated as needed.

[0038]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples.

[Embodiment] A painted molded product having a painted sheet laminated on its surface was manufactured by an injection molding simultaneous painting apparatus as shown in FIGS.

The painting sheet to be used is an ink obtained by adding a coloring pigment such as a petal pattern to a binder of an acrylic resin on one side of a transparent 125 μm-thick acrylic resin film of a methyl methacrylate-butyl methacrylate copolymer system. Form a decorative layer with a combination of three colors,
Furthermore, from the top of the decoration layer, a brown ABS of 500 μm thickness
A resin sheet was adhered, and an adhesive layer made of a vinyl chloride-vinyl acetate copolymer was formed on the surface of the ABS resin sheet to prepare a sheet with a picture. In addition, the ABS sheet side of the painted sheet is the back side, that is, the injection resin side.

Further, for molding a molded product, a length of 300 m
An injection mold was prepared from which a rectangular parallelepiped molded product of m, 200 mm in width and 40 mm in depth was obtained. The female mold of this mold has a ventilation hole for sucking air inside the mold for sheet preforming, and has a guide groove for passing the endless annular chain of the sheet feeding device, and the parting surface is a curved surface. There is no plane. Heat-resistant ABS resin was used as the molding resin. The heat deformation temperature of the heat-resistant ABS resin is 103 ° C. The temperature of the injection resin was 240 ° C., and the mold temperature was 60 ° C.

In the forming process, first, the leading end portion of the continuous band-shaped picture sheet S which is unwound from the roll R and held by the sheet holding mechanism 55 is gripped by the sheet pulling mechanism 57 and both ends in the sheet width direction. The sheet with the picture was fed by a length of one shot through the sheet grips 60 in the released state through both ends of the sheet.
Then, after the sheet gripping chuck 60 grips the pictorial sheet, the sheet pull-out mechanism 57 releases the grip of the pictorial sheet, cuts the downstream side of the pictorial sheet fed in this state by the sheet cutter 56, and performs one shot. It was a sheet with a sheet of paper. A preheater 4 made of a ceramic panel heater is provided at a position below the painted sheet at this position at a distance of 50 mm from the painted sheet, and the surface temperature of the preheated heater is set to 150 ° C., and for 20 seconds, The painted sheet was radiantly heated without contact. The temperature of the painted sheet is 2
The temperature was 80 ° C. at the time of heating for 0 seconds. Since the preheating step of the painted sheet is performed during the preforming of the painted sheet in the previous cycle and the injection molding using the same, the cycle time does not increase.

Thereafter, the endless annular chain 50 is sent,
The painted sheet that was gripped and preheated was conveyed onto the parting surface 14 of the female mold 12 and pressed and fixed to the parting surface with the clamper 20 to complete the supply of the painted sheet onto the mold. It took 10 seconds to supply the painted sheet, during which time the temperature of the painted sheet dropped from 80 ° C to 65 ° C. Thereafter, the heater is different from the preheating heater.
A heating unit 71 composed of a ceramic panel heater advances a single plate-shaped heater 70 between the male and female molds from a retreat position outside the mold to a surface temperature of 350 ° C. and a non-contact distance of 40 mm between the sheet and the heater. Was heated and softened by radiation heating. Ten seconds after the start of heating, the temperature of the painted sheet became 140 ° C., which was a temperature suitable for vacuum forming. Then, vacuum forming was performed using the female mold as a vacuum forming mold, and the painted sheet was placed along the cavity surface 13 of the female mold to complete the preliminary molding. Thereafter, the heater 70 is retracted to the outside of the mold, both molds are clamped, and the injection resin heated and melted is injected into a cavity formed by both molds. After the resin is cooled and solidified, the mold is opened. Thus, a painted molded product on which the painted sheet was laminated was obtained.

Comparative Example In the example, a painted molded article was obtained without preheating the painted sheet. Without preheating, it took 20 seconds to heat the painted sheet to 140 ° C. with a heater. The heating time required was 10 seconds longer than in the example, and the cycle time increased accordingly.

[0045]

According to the method and apparatus for simultaneous painting by injection molding according to the present invention, the painting sheet is preheated before being supplied to the mold, so that the sheet is heated to the required vacuum molding temperature on the mold. The time required to do so can be reduced. Therefore, the time of the mold opening state can be shortened, and the productivity can be improved by shortening the cycle time. Also, when supplying the pre-heated painting sheet into the mold, the painting sheet is gripped at least at both ends in the width direction with respect to the conveyance direction of the painting sheet, and supplied with the length of both sides of the painting sheet in the width direction being constant. By doing so, even if the painting sheet is preheated, the painting sheet maintains its length in the width direction, so that the painting sheet is reliably prevented from deformation and distortion when the painting sheet is supplied on the mold, The painted sheet can be supplied to the mold extremely stably. In addition, by performing the preheating and heating of the painting sheet by non-contact heating, the painting sheet is fused to the heater with the adhesive layer or the like, and the supply of the painting sheet to the mold does not become unstable, There is no trace of the painted sheet contacting the heater on the appearance of the molded product, and the appearance does not deteriorate.

[Brief description of the drawings]

FIG. 1 is a side view showing the overall configuration of an injection molding simultaneous painting apparatus according to the present invention.

FIG. 2 is a perspective view showing the vicinity of a preheater and a sheet feeding device in FIG. 1;

FIG. 3 is a partially enlarged side view showing an endless annular chain and a sheet gripping chuck in the sheet feeding device of FIG. 1;

FIG. 4 is a partially enlarged cross-sectional view illustrating a guide groove provided in the endless annular chain, the sheet gripping chuck, and the female die of FIG. 3;

FIG. 5 is a partially enlarged cross-sectional view for explaining the operation of the endless annular chain and the sheet gripping chuck of FIG. 3;

[Description of Signs] 1 support frame 3 rail 4 preheater (sheet preheating means) 5 sheet supply device (sheet supply means) 6 base frame 7 connecting member 8 connecting plate 9 ram 11 movable plate 12 female mold 13 cavity surface 14 parting Surface 20 Clamper 21 Concave portion 24 Connecting rod 25 Male type 31 Fixed plate 32 Injection nozzle 33 Core portion 34 Male type parting surface 36 Supply side guide groove 36A Intermediate wall 36a Opening groove 36c, 36d Position control concave portion 38 Bottom side guide groove 41 45 Sprocket wheel 46, 47 Sprocket wheel for applying tension 50 Endless annular chain 55 Sheet holding mechanism 56 Sheet cutter 57 Sheet pull-out mechanism 60 Sheet gripping chuck 61 Support member 62 Large-diameter roller 63 Small-diameter roller 64 Support plate 65 Fixed receiving part 6 Movable pressing piece portion 67 the coil spring 68 roller 70 heater (sheet heating means) 71 plate heating portion 72 second plate-shaped heating portion 75 holding case R roll S decorative sheet

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // B29L 9:00

Claims (6)

[Claims] After supplying a painting sheet onto a mold, the painting sheet is heated to a temperature not lower than the heat deformation temperature of the sheet, and the painting sheet is moved along the cavity surface of the mold by evacuation from the inside of the mold. In the simultaneous injection molding and painting method, in which the resin in a fluid state is injected into the cavity and bonded to the resin, the painted sheet is heated to a heat deformation temperature of the sheet before the painted sheet is supplied onto the mold. Injection molding simultaneous painting method, pre-heated to a temperature less than. 2. The simultaneous painting method for injection molding according to claim 1, wherein when the pre-heated painted sheet is supplied into a mold, the painted sheet is gripped at least at both ends in the width direction with respect to the conveying direction of the painted sheet. Injection molding simultaneous painting method, in which the length of both sides in the width direction of the painting sheet is supplied in a constant state. 3. The simultaneous painting method for injection molding according to claim 1, wherein preheating and heating of the painting sheet are performed by non-contact heating. 4. After supplying the painting sheet onto the mold, the painting sheet is heated to a temperature not lower than the heat deformation temperature of the sheet, and the painting sheet is moved along the cavity surface of the mold by evacuation from the inside of the mold. In the simultaneous injection molding and painting apparatus for performing the injection molding simultaneous painting method of injecting the resin in the fluid state into the cavity and bonding the painted sheet and the resin to the cavity, the painted sheet before being supplied to the mold is used. Sheet preheating means for preheating the sheet to a temperature lower than the heat deformation temperature, sheet heating means for heating the preheated painted sheet supplied into the mold to a temperature equal to or higher than the heat deformation temperature of the sheet, and sheet preheating means for the sheet And a sheet supply means for supplying the pre-heated painted sheet to the inside of the mold. 5. The simultaneous painting apparatus for injection molding according to claim 4, wherein the sheet supply means is configured to supply the preheated painted sheet into the mold at least at both ends in the width direction with respect to the conveying direction of the painted sheet. An injection molding simultaneous painting apparatus that grips a painting sheet and supplies the painting sheet with both sides in the width direction being constant. 6. The simultaneous injection molding and painting apparatus according to claim 4, wherein preheating and heating of the painting sheet are performed by non-contact heating.